fix(handler): fix build error mysql#111

[summary]
As var SHANNON_MAX_POPULATION_BUFFER_SIZE type is uint64, but MYSQL_SYSVAR_ULONG is used, fixed it with MYSQL_SYSVAR_ULONGLONG

Author: hustjieke

storage/rapid_engine/handler/ha_shannon_rapid.cc

@@ -1029,7 +1029,7 @@ static MYSQL_SYSVAR_ULONG(
     ShannonBase::SHANNON_MAX_MEMRORY_SIZE, 0,
     ShannonBase::SHANNON_MAX_MEMRORY_SIZE, 0);
 
-static MYSQL_SYSVAR_ULONG(rapid_populate_buffer_size_max,
+static MYSQL_SYSVAR_ULONGLONG(rapid_populate_buffer_size_max,
                           ShannonBase::Populate::population_buffer_size,
                           PLUGIN_VAR_OPCMDARG | PLUGIN_VAR_READONLY,
                           "Number of populate buffer size that must not be 10% "